EP3737210B1 - Induction heating device - Google Patents

Description

The invention relates to an induction furnace device according to the preamble of claim 1 and a method for operating an induction furnace device according to the preamble of claim 13.

An induction furnace device is already known from the prior art, which has an inductor and a further inductor. A supply unit of the induction furnace device has a heating frequency unit, which is assigned to the inductor, and a further heating frequency unit, which is assigned to the further inductor. In a heating-up operating state, a control unit operates the inductor by means of the heating frequency unit and the further inductor by means of the further heating frequency unit continuously, each with a maximum heating power of 1.8 kW.

The document WO 2018/116058 A1 discloses an induction furnace having an induction heating element and a control unit that operates the induction heating element in at least one preheat mode.

The object of the invention is in particular to provide a generic device with improved properties in terms of ease of use. The object is achieved according to the invention by the features of claims 1 and 13, while advantageous configurations and developments of the invention can be found in the dependent claims.

The invention is based on an induction furnace device with at least one inductively heatable heating element, with at least one control unit and with at least one inductor, which is provided for inductively heating the heating element.

It is proposed that the control unit operates the inductor in a pulsed manner in a heating-up operating state.

Such a design makes it possible in particular to achieve a high level of operating convenience. In particular, high efficiency can be achieved, in particular with regard to a heating-up time and/or the energy required for heating. In particular, a high level of flexibility with regard to operation of the inductor be made possible, since in particular a pulse duration and/or a cycle duration can be flexibly selected.

An “induction furnace device” is to be understood in particular as meaning at least a part, in particular a subassembly, of an induction furnace. An “oven” is to be understood in particular as a unit which has at least one muffle which delimits and/or defines at least one cooking chamber and which is intended in particular to provide energy for the purpose of heating at least one item to be cooked in the cooking chamber. An “induction oven” is to be understood in particular as an oven which is provided for the inductive provision of energy for the purpose of heating the food to be cooked located in the cooking space. The induction oven could, for example, have an induction grill and/or an induction baking oven and/or an induction cooker. In particular, the induction oven could be in the form of an induction grill and/or an induction baking oven and/or an induction cooker.

The induction furnace device has in particular at least one muffle, which in particular at least partially defines and/or delimits at least one cooking chamber. In particular, the muffle has at least one cooking space wall which at least partially defines and/or delimits the cooking space. At least one cooking chamber wall of the muffle could be a rear wall and/or a side wall and/or a bottom wall and/or a top wall, for example. The phrase that an object defines and/or delimits the cooking space "at least partially" is intended to mean in particular that the object defines and/or delimits the cooking space alone or together with at least one other object. The additional object could be an appliance door and/or an additional cooking chamber wall, for example.

An "inductively heatable" heating element is to be understood in particular as a heating element which is provided for inductively receiving energy and which, depending on the inductively received energy in an operating state, provides heating energy for heating the food to be cooked in the cooking chamber. For example, the heating element could provide the heating energy inductively. The heating element could advantageously provide the heating energy in the form of heat. In particular, the heating element could change depending on heat the inductively received energy and provide the heating energy in the form of heat caused in particular by the inductively received energy.

A "heating element" is to be understood in particular as an element which is provided in particular in an operating state for receiving energy, in particular inductively, and which is provided in an operating state for supplying energy to at least one item to be cooked for the purpose of heating the item to be cooked. In particular, the heating element differs from a cooking utensil and/or from a cooking tray and/or from a baking tray and/or from a grating and/or from a fat collecting tray. For example, the heating element could have at least a partial area of at least one cooking chamber wall and/or be designed at least as a partial area of at least one cooking chamber wall. The heating element could, for example, be made of sheet metal and in particular be arranged in the vicinity of at least one cooking chamber wall and in particular at least to a large extent inside the cooking chamber.

In particular, the heating element could be formed at least to a large extent from at least one inductively heatable material. For example, the heating element could be formed at least in large part from at least one ferromagnetic material, such as iron. “At least a large part” is to be understood in particular as a proportion, in particular a proportion by mass and/or a proportion by volume and/or a proportion of a number of at least 70%, in particular at least 80%, advantageously at least 90% and preferably at least 95% will.

The control unit is in particular an electronic unit which, in an operating state, controls and/or regulates at least the inductor and in particular at least one further inductor and/or at least one supply unit. The control unit has in particular at least one arithmetic unit and in particular in addition to the arithmetic unit at least one memory unit in which in particular at least one open-loop and/or closed-loop control program is stored which is intended in particular for execution by the arithmetic unit.

In an operating state, the inductor provides energy, in particular inductively, and transmits the provided energy, in particular inductively, at least to the heating element. In particular, the inductor has at least one coil and, in an operating state, provides inductive energy, in particular by means of the coil, in particular for inductive energy transmission, advantageously at least to the heating element.

In particular, the inductor inductively transmits energy to the heating element at least in a partial time interval of the heating-up operating state and heats the heating element in particular in the partial time interval of the heating-up operating state by means of the inductively provided energy.

A "heating-up operating state" is to be understood in particular as an operating state in which the control unit heats at least one object, in particular the cooking chamber and/or the heating element and/or an item to be cooked, from at least one initial temperature to at least one setpoint temperature, which is in particular significantly greater than the starting temperature. In particular, the target temperature is at least 1.1 times, in particular at least 1.2 times, advantageously at least 1.5 times, particularly advantageously at least 2 times, preferably at least 3 times, particularly preferably at least 5 times and particularly preferably at least 8 times times the initial temperature. The starting temperature has in particular a maximum value of 200° C., in particular a maximum of 150° C., advantageously a maximum of 120° C., particularly advantageously a maximum of 100° C., preferably a maximum of 80° C., particularly preferably a maximum of 50° C. and especially preferably of a maximum of 30 °C. In particular, the starting temperature has a value which at least essentially corresponds to room temperature.

The heating-up operating state is in particular free of interruptions, in particular for the purpose of heating food to be cooked. In particular, the control unit in the heating mode supplies the heating element with an average of at least 20%, in particular at least 25%, advantageously at least 30%, particularly advantageously at least 35%, preferably at least 40% and particularly preferably at least 45% a total duration of the heating operating state to energy and thus increases in particular a temperature of the heating element.

In particular, the induction furnace device has at least one further heating element, in particular in addition to the heating element. In the heating operating state, the control unit guides in particular at least one object, in particular the heating element and/or the additional heating element, on average over a proportion of at least 40%, in particular at least 50%, advantageously at least 60%, particularly advantageously at least 70%, preferably by at least 80% and particularly preferably by at least 90% of a total duration of the heating operating state and thus increases in particular a temperature of the object, in particular the heating element and/or the further heating element.

In particular, the induction furnace device has at least one supply unit, which in particular has at least one heating frequency unit and which, in particular by means of the heating frequency unit, provides in particular energy, in particular in the form of high-frequency alternating current. The phrase that the control unit “operates” an object, in particular the inductor and/or the additional inductor, in a pulsed manner should be understood in particular to mean that the control unit controls the supply unit and supplies energy to the object, in particular by means of the supply unit, whereupon the object in particular provides further energy, in particular in inductive form, as a function of the energy supplied.

The phrase that the control unit operates the inductor in a "pulsed" manner in the heating-up operating state is to be understood in particular to mean that the control unit operates the inductor in the heating-up operating state in at least one sub-time interval and deactivates it in at least one further sub-time interval that differs from the sub-time interval . In particular, the control unit operates the inductor intermittently and/or non-continuously in the heating mode. The control unit could operate the inductor, and in particular the further inductor, in the heating operating state, in particular by means of multiplexing. In particular, a frequency with which the control unit operates and/or deactivates the inductor and/or the additional inductor in the heating operating state is significantly greater than a switching frequency of the heating frequency unit, by means of which the control unit operates the inductor and/or the additional inductor.

A time sub-interval t ₁ , in which the control unit operates the inductor in the heating mode, has a value of at least 1 ms, in particular at least 5 ms, advantageously at least 8 ms, particularly advantageously at least 10 ms, preferably at least 15 ms and particularly preferably from at least 20 ms. In particular, a time sub-interval t ₁ , in which the control unit operates the inductor in the heating operating state, has a value of no more than 300 s, in particular no more than 200 s, advantageously no more than 180 s, particularly advantageously no more than 150 s, preferably no more than 120 s and particularly preferably from a maximum of 100 s.

Another time sub-interval t ₂ , in which the control unit operates the other inductor in the heating operating state, has a value of at least 1 ms, in particular at least 5 ms, advantageously at least 8 ms, particularly advantageously at least 10 ms, preferably at least 15 ms and particularly preferably from at least 20 ms. In particular, a further sub-interval t ₂ , in which the control unit operates the further inductor in the heating operating state, has a value of at most 300 s, in particular at most 200 s, advantageously at most 180 s, particularly advantageously at most 150 s, preferably at most 120 s and particularly preferably from a maximum of 100 s.

“Provided” should be understood to mean, in particular, specially programmed, designed and/or equipped. The fact that an object is provided for a specific function is to be understood in particular to mean that the object fulfills and/or executes this specific function in at least one application and/or operating state.

For example, the controller could operate the inductor erratically in the heat-up mode. Advantageously, the control unit regularly operates the inductor in the heating operating state. In the heating-up operating state, the control unit preferably operates the inductor and in particular the further inductor cyclically in a pulsed manner with at least one cycle duration. In particular, the cycle duration includes the time sub-interval t ₁ and in particular the further time sub-interval t ₂ . In the heating operating state, the control unit operates the inductor and in particular the further inductor in a regularly recurring sequence. In particular, the Control unit in the heating mode following an expiration of the cycle time, in particular directly and / or avoiding a pause, another cycle time. “Cyclic” is to be understood in particular as regularly and/or periodically. As a result, particularly simple control and/or less programming effort for the control unit can be achieved, which means that particularly low costs and thus particularly high operator satisfaction can be achieved.

In addition, it is proposed that the cycle duration in at least one time interval of the heating operating state should have a value of at least 10 ms, in particular at least 15 ms, advantageously at least 20 ms, particularly advantageously at least 30 ms, preferably at least 40 ms and particularly preferably at least 60 ms. In particular, the cycle duration in at least one time interval of the heating-up operating state, in particular in the time interval of the heating-up operating state, has a value of no more than 600 s, in particular no more than 500 s, advantageously no more than 400 s, particularly advantageously no more than 300 s, preferably no more than 250 s and particularly preferably of a maximum of 200 s. As a result, the cycle duration can be selected in particular in an optimal and/or flexible manner, as a result of which in particular an optimal and/or flexible heating of the heating element can be made possible.

Furthermore, it is proposed that the control unit determines the cycle duration in the heating-up operating state as a function of at least one current heating parameter in relation to at least one reference heating parameter. In the heating operating state, the control unit determines the cycle duration in particular as a function of a ratio of the current heating parameter to the reference heating parameter and advantageously as a function of a distance between the current heating parameter and the reference heating parameter. In particular, the reference heating parameter and the current heating parameter correspond to one another. The current heating parameter, and in particular the reference heating parameter, could be, for example, a temperature and/or a heating power and/or a heating power density and/or a heating stage and/or a heating duration. For example, the control unit could receive the reference heating parameter from at least one external unit. For example, the external unit could be an external database and/or a cell phone and/or a tablet and/or a computer. For example, the control unit could have at least one memory unit in which the reference heating parameter in particular could be stored. The control unit could receive the reference heating parameter, for example, from at least one operator interface, in particular as a function of at least one operator input. The induction furnace device has in particular at least one and advantageously at least the operator interface, which is provided in particular for an input and/or operator input of at least one operating parameter, such as the reference heating parameter and/or a heating stage and/or a heating power and/or a heating duration. The induction furnace device has in particular at least one sensor unit which is provided in particular for detecting the current heating parameter. For example, the sensor unit could be arranged at least partially within the cooking space. The sensor unit could have at least one detector, for example, which could be arranged in particular inside the cooking chamber and in particular provided for detecting the current heating parameter. In this way, in particular, flexible determination of the cycle duration can be made possible, as a result of which, in particular, an optimal and/or short heating-up operating state can be achieved. In particular, unexpected events can be reacted to at short notice, as a result of which a high safety standard can be achieved in particular.

The current heating parameter, and in particular the reference heating parameter, could have a heating power and/or a heating line density and/or a heating stage and/or a heating duration, for example. The current heating parameter, and in particular the reference heating parameter, preferably has a temperature and is in particular in the form of a temperature. In particular, the reference heating parameter has at least one target temperature and is designed in particular as a target temperature. In this way, in particular, a simple and/or transparent determination of the cycle duration can be achieved.

In addition, it is proposed that the control unit operates the inductor, and in particular the further inductor, with a shorter cycle time in the heating operating state, the smaller the difference between the reference heating parameter and the current heating parameter, in order in particular to avoid flicker. In which In the heating-up operating state, the control unit selects the cycle time to be longer, the greater the distance between the current heating parameter and the reference heating parameter. The control unit operates the inductor, and in particular the further inductor, in the heating-up operating state with a heating power that is all the greater the greater the difference between the reference heating parameter and the current heating parameter. In order in particular to avoid fluctuations in a total output power and thus in particular flicker, the control unit operates the inductor, and in particular the further inductor, in the heating-up operating state with a longer cycle time the greater the difference between the reference heating parameter and the current heating parameter. As a result, a particularly high level of operating convenience can be achieved in particular. In particular, a flicker standard can be complied with.

It is also proposed that the induction furnace device has at least one additional heating element and at least one additional inductor, in particular at least the additional inductor, which is provided in particular for inductive heating of the additional heating element and which the control unit operates in a pulsed manner in the heating operating state. In particular, the control unit operates the further inductor in the heating operating state cyclically with at least one cycle time, in particular with the cycle time, pulsed. In particular, the inductor and the further inductor are arranged on opposite sides of the cooking chamber and/or the muffle. In particular, the inductor is assigned to the heating element and the additional inductor is assigned to the additional heating element. The heating element and the further heating element are arranged in particular on opposite sides of the cooking chamber and/or the muffle. In this way, in particular, a high level of efficiency and/or a short heating-up time can be achieved, as a result of which, in particular, a high level of operating convenience can be achieved.

For example, in the heating-up operating state, the control unit could operate the inductor and the further inductor in pulsed fashion at least in sections at the same time. In the heating-up operating state, the control unit preferably operates the inductor and the further inductor alternately and, in particular, pulsed without overlapping. “Alternating” should be understood to mean, in particular, alternately and/or alternately. In this way, in particular, a particularly efficient configuration can be made possible. In particular, a particularly short heating-up time and/or a high temperature of the Heating element and/or the further heating element can be made possible since the inductor, and in particular the further inductor, can be operated with increased power, in particular in each case in a partial time interval.

In addition, it is proposed that the induction furnace device has at least one supply unit and at least one switching unit, by means of which the control unit optionally electrically connects the inductor or the further inductor to the supply unit in the heating operating state. The supply unit has, in particular in addition to the heating frequency unit, at least one further heating frequency unit, which is provided in particular for providing energy, in particular in the form of high-frequency alternating current. The heating frequency unit is assigned in particular to the inductor. In particular, the additional heating frequency unit is assigned to the additional inductor. The switching unit is arranged in particular electrically between the supply unit and the inductor and/or the additional inductor. In particular, the switching unit is provided for establishing and/or separating an electrically conductive connection between the supply unit and the inductor and/or the further inductor, specifically in particular as a function of a control signal from the control unit. A "switching unit" is to be understood in particular as a unit which is intended to change a current-carrying property when a switching position changes. The switching unit could, for example, have at least one switching element which, for example, has at least one relay and/or at least one transistor and could be designed in particular as a relay and/or as a transistor. In particular, the switching unit could interrupt a first conduction path in a first switching position of the switching element and in particular prevent a current flow via the first conduction path. The switching unit could, for example, close the first conduction path in a second switching position of the switching element and in particular allow and/or enable a current flow via the first conduction path. In this way, in particular, a high degree of flexibility can be achieved. In particular, due to a long cycle time, a small number of switching operations of the switching unit can be achieved, as a result of which a long service life and/or low material wear can be made possible. It can in particular be a low noise level, in particular due to a small number of Switching operations can be achieved, whereby in particular a particularly high level of operating comfort can be achieved.

Furthermore, it is proposed that the control unit, in the heating-up operating state, switches the switching unit, in particular exclusively, into a currentless state. The control unit switches the switching unit, in particular in the heating operating state, in particular exclusively, within a switching time interval in which the control unit in particular deactivates and/or interrupts the provision of energy by the supply unit. For example, the control unit could interrupt at least one electrical connection of the supply unit to a mains voltage in the switching time interval, for example by switching at least one input switching unit. The induction furnace device could, for example, have at least one and advantageously at least the input switching unit, which could be arranged in particular electrically between a mains voltage and the supply unit and by means of which the control unit could in particular establish and/or disconnect an electrical connection between the mains voltage and the supply unit. Particularly alternatively or additionally, the control unit could, for example, deactivate the heating frequency unit and in particular the further heating frequency unit in the switching time interval and thus in particular deactivate and/or interrupt the provision of energy by the supply unit. The switching time interval t _Rsw , in which the control unit deactivates and/or interrupts the provision of energy by the supply unit, has a value of at least 0.1 ms, in particular at least 0.2 ms, advantageously at least 0.5 ms, in particular advantageously from at least 0.8 ms, preferably from at least 1 ms and particularly preferably from at least 2 ms. In particular, the switching time interval t _Rsw , in which the control unit deactivates and/or interrupts the provision of energy by the supply unit, has a maximum value of 100 ms, in particular a maximum of 80 ms, advantageously a maximum of 60 ms, particularly advantageously a maximum of 50 ms, preferably from a maximum of 40 ms and particularly preferably from a maximum of 30 ms. In this way, in particular, a durable design and/or less material wear can be made possible, as a result of which a functional design can be provided to an operator, in particular over an extremely long period of time.

It is also proposed that the inductor and/or the further inductor be provided for providing top heat and/or bottom heat. In one installation position, the inductor could be arranged below the muffle, for example, and the further inductor could be arranged in particular above the muffle. In particular, the inductor could be arranged in an installed position above the muffle and the further inductor could be arranged in particular below the muffle. In this way, in particular, a high level of efficiency and/or a particularly high level of operating convenience can be achieved.

In addition, it is proposed that the control unit, in the heating-up operating state, activate the inductor, in particular in the time sub-interval t ₁ , with a heat output of at least 1.5 kW, in particular at least 1.8 kW, advantageously at least 2 kW, particularly advantageously at least 2 5 kW, preferably at least 3 kW and more preferably at least 3.5 kW. In particular, the control unit operates the additional inductor in the heating operating state, in particular in the additional time sub-interval t ₂ , with a heat output of at least 1.5 kW, in particular at least 1.8 kW, advantageously at least 2 kW, particularly advantageously at least 2.5 kW, preferably at least 3 kW and more preferably at least 3.5 kW. In particular, this enables a particularly short heating-up time and/or a high temperature of the heating element and/or the additional heating element, since the inductor, and in particular the additional inductor, can be operated with increased power, in particular in each partial time interval.

The heating element could be arranged, for example, inside the cooking chamber and in particular in the vicinity of the cooking chamber wall. The induction oven device preferably has at least one and advantageously at least the cooking chamber wall which at least largely defines the heating element. In particular, the heating element is designed as at least a partial area of the cooking chamber wall and is defined and/or formed by at least one partial area of the cooking chamber wall. The cooking chamber wall, which in particular defines the heating element at least to a large extent, is in particular a top wall and/or a bottom wall. The induction oven device has, in particular, at least one further cooking chamber wall, which at least largely defines the further heating element and which in particular is on a side of the cooking chamber opposite the cooking chamber wall is arranged. In this way, in particular, a small number of components and/or a small amount of stock can be achieved.

A particularly high level of operating comfort can be achieved in particular by an induction furnace with at least one induction furnace device according to the invention.

Ease of use can be further increased in particular by a method for operating an induction furnace device according to the invention with at least one inductively heatable heating element and with at least one inductor, which is provided for inductively heating the heating element, with the inductor being operated in a pulsed manner in a heating-up operating state.

The induction furnace device should not be limited to the application and embodiment described above. In particular, the induction furnace device can have a number of individual elements, components and units that differs from the number specified here in order to fulfill a function described herein.

Further advantages result from the following description of the drawing. Exemplary embodiments of the invention are shown in the drawing. The drawing, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into further meaningful combinations.

Fig. 1

einen Induktionsofen mit einer Induktionsofenvorrichtung in einer schematischen Darstellung,

Fig. 2

einen Ausschnitt eines Schaltbilds der Induktionsofenvorrichtung in einer schematischen Darstellung,

Fig. 3

ein Diagramm, in welchem eine Gesamtausgangsleistung über einer Zeit aufgetragen ist, in einer schematischen Darstellung,

Fig. 4

ein Diagramm, in welchem eine Ausgangsleistung eines Induktors der Induktionsofenvorrichtung über einer Zeit aufgetragen ist, in einer schematischen Darstellung,

Fig. 5

ein Diagramm, in welchem eine Ausgangsleistung eines weiteren Induktors der Induktionsofenvorrichtung über einer Zeit aufgetragen ist, in einer schematischen Darstellung,

Fig. 6

ein Diagramm, in welchem eine Temperatur eines Heizelements der Induktionsofenvorrichtung über einer Zeit aufgetragen ist, in einer schematischen Darstellung,

Fig. 7

ein Diagramm, in welchem ein aktueller Heizparameter, welcher eine Temperatur eines Garraums der Induktionsofenvorrichtung aufweist, über einer Zeit aufgetragen ist, in einer schematischen Darstellung,

Fig. 8

ein Diagramm, in welchem eine Temperatur eines weiteren Heizelements der Induktionsofenvorrichtung über einer Zeit aufgetragen ist, in einer schematischen Darstellung,

Fig. 9

ein Diagramm, in welchem eine Durchschnittsleistung des Induktors über einer Zeit aufgetragen ist, in einer schematischen Darstellung,

Fig. 10

ein Diagramm, in welchem eine Zyklusdauer über einer Zeit aufgetragen ist, in einer schematischen Darstellung und

Fig. 11

ein Diagramm, in welchem eine Durchschnittsleistung des weiteren Induktors über einer Zeit aufgetragen ist, in einer schematischen Darstellung.

Show it:

1

an induction furnace with an induction furnace device in a schematic representation,

2

a section of a circuit diagram of the induction furnace device in a schematic representation,

3

a diagram in which a total output power is plotted over time, in a schematic representation,

4

a diagram in which an output power of an inductor of the induction furnace device is plotted over time, in a schematic representation,

figure 5

a diagram in which an output power of a further inductor of the induction furnace device is plotted over time, in a schematic representation,

6

a diagram in which a temperature of a heating element of the induction furnace device is plotted over time, in a schematic representation,

7

a diagram in which a current heating parameter, which has a temperature of a cooking chamber of the induction oven device, is plotted over time, in a schematic representation,

8

a diagram in which a temperature of a further heating element of the induction furnace device is plotted over time, in a schematic representation,

9

a diagram in which an average power of the inductor is plotted over time, in a schematic representation,

10

a diagram in which a cycle duration is plotted against a time, in a schematic representation and

11

a diagram in which an average power of the further inductor is plotted over time, in a schematic representation.

figure 1 4 shows in particular an induction furnace 42a. For example, the induction oven 42a could be designed as an induction grill and/or as an induction cooker. In the present exemplary embodiment, the induction oven 42a is designed in particular as an induction oven.

The induction furnace 42a has in particular at least one and advantageously exactly one induction furnace device 10a. For example, the induction oven device 10a could be designed as an induction grill device and/or as an induction cooker device. In the present exemplary embodiment, the induction oven device 10a is designed in particular as an induction oven device.

The induction furnace device 10a has in particular at least one and advantageously exactly one muffle 44a. In particular, the muffle 44a at least partially delimits at least one, and advantageously exactly one, cooking space 46a. The muffle 44a delimits the cooking chamber 46a at least substantially, in particular together with a cooking appliance door 48a. The induction oven device 10a has in particular at least one and advantageously at least the cooking appliance door 48a.

In the present exemplary embodiment, the induction furnace device 10a has, in particular, five cooking chamber walls 50a. The cooking chamber walls 50a are in particular part of the muffle 44a. The cooking chamber walls 50a, in particular together with the cooking appliance door 48a, at least essentially define the cooking chamber 46a.

One of the cooking chamber walls 50a is designed in particular as a bottom wall 52a. One of the cooking chamber walls 50a is designed in particular as a top wall 54a. One of the cooking chamber walls 50a is designed in particular as a rear wall 56a. Two of the cooking chamber walls 50a are in particular each formed as a side wall 58a, 60a. In the following, in particular, only one of the cooking chamber walls 50a is described.

The induction furnace device 10a has in particular at least one and advantageously precisely one operator interface 62a, in particular for entering and/or selecting operating parameters, for example a heating power and/or a heating power density and/or a heating zone. The operator interface 62a is provided in particular for outputting a value of an operating parameter to an operator.

The induction furnace device 10a has in particular at least one and advantageously exactly one control unit 16a. The control unit 16a is provided in particular for carrying out actions and/or changing settings as a function of operating parameters entered by means of the user interface 62a. The control unit 16a regulates an energy supply to at least one inductor 18a, 20a (cf. figure 2 ).

In the present exemplary embodiment, the induction furnace device 10a has in particular at least one and advantageously exactly one, in particular at least the and advantageously precisely the inductor 18a. In particular, the inductor 18a is arranged outside of the cooking chamber 46a. In an installation position, the inductor 18a is arranged in particular above the top wall 54a and in particular in a region close to the top wall 54a. In particular, the inductor 18a is intended to provide top heat. In an operating state in which the control unit 16a operates the inductor 18a, the inductor 18a provides in particular an upper heat.

In particular, in addition to the inductor 18a, the induction furnace device 10a has in particular at least one and advantageously exactly one further inductor 20a. In particular, the additional inductor 20a is arranged outside of the cooking chamber 46a. In an installation position, the further inductor 20a is arranged in particular below the bottom wall 52a and in particular in a region close to the bottom wall 52a. In particular, the further inductor 20a is provided for providing bottom heat. In an operating state in which the control unit 16a operates the further inductor 20a, the further inductor 20a provides, in particular, bottom heat.

In particular as an alternative to the inductor 18a and the further inductor 20a, the induction furnace device 10a could in particular have a different number of inductors 18a, 20a. For example, the induction furnace device 10a could have precisely one, in particular a single, inductor 18a, 20a. Alternatively, the induction furnace device 10a could have, for example, at least three, in particular at least four, advantageously at least five and preferably a plurality of inductors 18a, 20a.

The induction furnace device 10a has in particular at least one and advantageously exactly one inductively heatable heating element 12a (cf. Figures 1 and 2 ). In particular, the inductor 18a is associated with the heating element 12a. In an operating state in which the control unit 16a operates the inductor 18a, the inductor 18a inductively heats the heating element 12a. In particular, the inductor 18a is provided for inductive heating of the heating element 12a.

The heating element 12a is arranged in particular in the vicinity of the inductor 18a. In particular, the heating element 12a is designed as a partial area of the top wall 54a. The top wall 54a defines the heating element 12a in particular at least to a large extent.

The induction furnace device 10a has in particular at least one and advantageously precisely one additional heating element 14a that can be heated inductively (cf. Figures 1 and 2 ). In particular, the additional inductor 20a is assigned to the additional heating element 14a. In an operating state in which the control unit 16a operates the further inductor 20a, the further inductor 20a inductively heats the further heating element 14a. In particular, the additional inductor 20a is provided for inductive heating of the additional heating element 14a.

The additional heating element 14a is arranged, in particular, in the vicinity of the additional inductor 20a. In particular, the additional heating element 14a is designed as a partial area of the bottom wall 52a. The bottom wall 52a defines the further heating element 14a in particular at least to a large extent.

For example, it is assumed, without loss of generality, that an operator enters a setpoint temperature by means of an operator input via the operator interface 62a, to which the control unit 16a is intended to heat the cooking chamber 16a in particular. In particular, the control unit 16a recognizes the setpoint temperature as a reference heating parameter. In particular, depending on the operator input, the control unit 16a starts a heating-up operating state in which the control unit 16a heats up the cooking chamber 46a by operating the inductor 18a and/or the further inductor 20a.

In the following reference is made to the Figures 3 to 5. Figure 3 shows a diagram in which a total output power is plotted over time. On an ordinate 64a of figure 3 a total output power is plotted. On an abscissa 66a of figure 3 a time is applied. An average output power of the inductors 18a, 20a is in figure 3 denoted as ∑P _T.

figure 4 shows a diagram in which an output power of the inductor 18a is plotted over time. On an ordinate 68a of figure 4 an output power of the inductor 18a is plotted. On an abscissa 70a of figure 4 a time is applied. An average output power of the inductor 18a is in figure 4 referred to as EP _T1 .

figure 5 shows a diagram in which an output power of the further inductor 20a is plotted over time. On an ordinate 72a of figure 5 an output power of the further inductor 20a is plotted. On an abscissa 74a of figure 5 a time is applied. An average output power of the further inductor 20a is in figure 5 denoted as ∑P _T2 .

In the heating operating state, the control unit 16a operates the inductor 18a, in particular in a pulsed manner (cf. Figures 3 to 5 ). In particular, the control unit 16a operates the inductor 18a in the heating operating state in a cyclic manner with at least one cycle duration 22a in a pulsed manner. In particular, the controller 16a operates the inductor 18a in the heat-up mode in a time sub-interval 24a of the cycle duration 22a. In a further time sub-interval 26a of the cycle duration 22a, the control unit 16a deactivates the inductor 18a.

In the heating operating state, the control unit 16a operates the further inductor 20a, in particular in a pulsed manner. In particular, the control unit 16a operates the further inductor 20a cyclically in the heating operating state with at least one cycle duration 22a. In particular, the control unit 16a deactivates the further inductor 20a in the heating operating state in the time sub-interval 24a of the cycle duration 22a. In the further time sub-interval 26a of the cycle duration 22a, the control unit 16a operates the further inductor 20a.

The control unit 16a operates the inductor 18a and the further inductor 20a without overlap in the heating operating state. In particular, in the heating operating state, the control unit 16a operates the inductor and the further inductor in alternating pulses.

In the present exemplary embodiment, control unit 16a selects a value of at least 10 ms for time subinterval 24a, in which control unit 16a operates in particular inductor 18a. In particular, the control unit 16a selects a maximum value of 150 s for the time sub-interval 24a, in which the control unit 16a operates the inductor 18a in particular.

In the present exemplary embodiment, the control unit 16a selects a value of at least 10 ms for the additional time subinterval 26a, in which the control unit 16a operates the additional inductor 20a in particular. In particular, the control unit 16a selects a maximum value of 150 s for the additional time sub-interval 26a, in which the control unit 16a operates the additional inductor 20a in particular.

In particular for supplying energy to the inductor 18a and/or the further inductor 20a, the induction furnace device 10a has in particular at least one and advantageously precisely one supply unit 38a (cf. figure 2 ). In an operating state, for example in the heating-up operating state, the supply unit 38a provides high-frequency alternating current.

In particular, the supply unit 38a has at least one and advantageously precisely one heating frequency unit 76a, which is provided in particular for providing high-frequency alternating current. The heating frequency unit 76a is assigned in particular to the inductor 18a.

In particular, the supply unit 38a has at least one and advantageously precisely one further heating frequency unit 78a, which is provided in particular for providing high-frequency alternating current. The further heating frequency unit 78a is assigned in particular to the inductor 18a.

The induction furnace device 10a has in particular at least one and advantageously exactly one switching unit 40a. The switching unit 40a is arranged and/or connected in particular electrically between the supply unit 38a and the inductor 18a and/or the further inductor 20a.

In particular, the switching unit 40a has at least one and advantageously exactly one switching element 80a, which is designed in particular as a changeover switch. The switching element 80a is assigned in particular to the heating frequency unit 76a. In particular, an electrical input connection of the switching element 80a is electrically conductively connected to the heating frequency unit 76a. A first electrical output connection of the switching element 80a is electrically conductively connected in particular to the inductor 18a. A second electrical output connection of the Switching element 80a is electrically conductively connected in particular to the further inductor 20a. In particular, the switching element 80a has at least one and advantageously exactly one switch 82a which, in particular as a function of activation by the control unit 16a, electrically conductively connects the input connection of the switching element 80a either to the first output connection of the switching element 80a or to the second output connection of the switching element 80a connects.

In particular, the switching unit 40a has at least one, and advantageously precisely one, further switching element 84a, which is designed in particular as a changeover switch. The further switching element 84a is assigned in particular to the further heating frequency unit 78a. In particular, an electrical input connection of the further switching element 84a is electrically conductively connected to the further heating frequency unit 78a. A first electrical output connection of the further switching element 84a is electrically conductively connected in particular to the inductor 18a. A second electrical output connection of the further switching element 84a is electrically conductively connected in particular to the further inductor 20a. In particular, the further switching element 84a has at least one and advantageously precisely one switch 86a which, in particular as a function of activation by the control unit 16a, connects the input terminal of the further switching element 84a either to the first output terminal of the further switching element 84a or to the second output terminal of the further Switching element 84a electrically conductively connects.

In the heating-up operating state, the control unit 16a electrically conductively connects the inductor 18a or the further inductor 20a to the supply unit 38a by means of the switching unit 40a. In the heating operating state, the control unit 16a connects the inductor 18a to the supply unit 38a, in particular to the heating frequency unit 76a and to the further heating frequency unit 78a, in particular by means of the switching unit 40a, in particular in the time division interval 24a.

In the heating operating state, the control unit 16a operates the inductor 18a, in particular with a heat output of at least 1.5 kW. In particular, the control unit 16a operates the inductor 18a in the heating operating state with the heating frequency unit 76a and with the further heating frequency unit 78a.

In particular, the control unit 16a, in particular by means of the switching unit 40a, connects the further inductor 20a to the supply unit 38a, in particular to the heating frequency unit 76a and to the further heating frequency unit 78a, in the further time sub-interval 26a. In the heating operating state, the control unit 16a operates the further inductor 20a, in particular with a heat output of at least 1.5 kW. In particular, the control unit 16a operates the further inductor 20a in the heating operating state with the heating frequency unit 76a and with the further heating frequency unit 78a.

In the heating-up operating state, the control unit 16a switches the switching unit 40a, in particular in a currentless state. In particular, in the heating-up operating state, the control unit 16a interrupts a provision of energy by the supply unit 38a. In the heating mode, the control unit 16a switches the switching unit 40a, in particular exclusively, in particular in a switching time interval 28a, which the control unit 16a executes in particular directly following the time sub-interval 24a and/or the further time sub-interval 26a.

In particular, in the heat-up operating state, the control unit 16a first executes the time sub-interval 24a in the cycle duration 22a. In particular, subsequent to the time division interval 24a, the control unit 16a in the heating-up operating state in the cycle duration 22a executes in particular the switching time interval 28a. In particular, following the switching time interval 28a, the control unit 16a executes in the heating-up operating state in the cycle duration 22a, in particular the further time sub-interval 26a. In particular, following the further time sub-interval 26a, the control unit 16a executes in the heating-up operating state in the cycle duration 22a, in particular the switching time interval 28a. The control unit 16a then carries out, in particular, a second cycle with a cycle duration 22a.

In the heating-up operating state, the control unit 16a determines the cycle duration 22a as a function of at least one current heating parameter in relation to the reference heating parameter. In particular, in the heating-up operating state, the control unit 16a determines the cycle duration 22a as a function of a difference between the reference heating parameter and the current heating parameter.

In particular, the reference heating parameter has a setpoint temperature, in particular of the cooking chamber 46a, and is in particular designed as a setpoint temperature. In the present exemplary embodiment, the reference heating parameter is specified in particular by an operator, in particular by an operator input, advantageously by means of the operator interface 62a. The current heating parameter has, in particular, a temperature, in particular a current temperature, in particular of the cooking chamber 46a, and is embodied in particular as a temperature, in particular a current temperature, in particular of the cooking chamber 46a.

In the heating-up operating state, the control unit 16a selects a value of at least 30 ms for the cycle duration 22a. In particular, the control unit 16a selects a maximum value of 300 s for the cycle duration 22a in the heating-up operating state Figures 6 to 11 .

figure 6 shows a diagram in which a temperature of the heating element 12a is plotted over time. On an ordinate 88a of figure 6 a temperature of the heating element 12a is plotted in a unit of degrees Celcius. On an abscissa 90a of figure 6 a time is plotted in a unit of seconds.

figure 7 shows a diagram in which a current heating parameter, which in particular has a current temperature of the cooking chamber 46a, is plotted over time. On an ordinate 92a of figure 7 a current heating parameter, which in particular has a current temperature of the cooking space 46a, is plotted in a unit of degrees Celsius. On an abscissa 94a of figure 7 a time is plotted in a unit of seconds.

figure 8 shows a diagram in which a temperature of the further heating element 14a is plotted over time. On an ordinate 96a of figure 8 a temperature of the further heating element 14a is plotted in a unit degree Celcius. On an abscissa 98a of figure 8 a time is plotted in a unit of seconds.

figure 9 shows a diagram in which an average power of the inductor 18a is plotted over time. On an ordinate 100a of figure 9 is a Average power of inductor 18a plotted in units of watts. On an abscissa 102a of figure 9 a time is plotted in a unit of seconds.

figure 10 shows a diagram in which a cycle duration Tc is plotted against a time. On an ordinate 104a of figure 10 a cycle time T _C is plotted in a unit of seconds. On an abscissa 106a of figure 10 a time is plotted in a unit of seconds.

figure 11 shows a diagram in which an average power of the further inductor 20a is plotted over time. On an ordinate 108a of figure 11 an average power of the further inductor 20a is plotted in a unit of watts. On an abscissa 110a of figure 11 a time is plotted in a unit of seconds.

In the heating-up operating state, in particular each cycle duration 22a has a value of at least 10 ms, in particular in at least one time interval 30a, 32a, 34a, 36a of the heating-up operating state, in particular in each time interval 30a, 32a, 34a, 36a of the heating-up operating state.

In the present exemplary embodiment, the first cycle duration 22a1 in the time interval 30a of the heating operating state has, in particular, a value of at least essentially 59.2 s. In particular, a second cycle duration 22a2 in a second time interval 30a of the heating operating state has a value of at least essentially 45.2 s. In a third time interval 34a of the heating operating state, a third cycle duration 22a3 has, in particular, a value of at least essentially 29 s. In particular, a fourth cycle duration 22a4 in a fourth time interval 36a of the heating operating state has a value of at least essentially 14.9 s.

In particular from the Figures 6, 8 and 10 It can be seen that a value of the cycle duration 22a is reduced as a function of time. In particular, in the heating-up operating state, the control unit 16a operates the inductor 18a with a shorter cycle time 22a, the smaller the difference between the reference heating parameter and the current heating parameter. In the heating operating state, the control unit 16a operates the further inductor 20a with a smaller cycle duration 22a, the smaller a difference between the reference heating parameter and the current heating parameter.

In a method for operating the induction furnace device 10a, the inductor 18a and the further inductor 20a in particular are operated in a pulsed manner in the heating-up operating state. In particular, the inductor 18a and the further inductor 20a are operated in a cyclically pulsed manner with at least one cycle duration 22a in the heating-up operating state. In the heating-up operating state, the inductor 18a and the further inductor 20a are operated in particular with a shorter cycle duration 22a, the smaller the difference between the reference heating parameter and the current heating parameter.

In particular, an occurrence of flicker is avoided in the method, in particular by a value of the cycle duration 22a, which is selected as large as possible while maintaining the reference heating parameter. A limit value for complying with a flicker standard is dependent in particular on a line variation and/or on a duration of a fluctuation and/or on a form factor.

In the heating-up operating state, the control unit 16a operates the inductor 18a in particular with a heating power which the control unit 16a determines in particular as a function of the reference heating parameter and which in particular corresponds at least essentially to a sum of an upper heating power P ₁ and a lower heating power P ₂ . In the heating operating state, the control unit 16a operates the additional inductor 20a, in particular with a heating power which the control unit 16a determines in particular as a function of the reference heating parameter and which in particular corresponds at least essentially to a sum of an upper heating power P ₁ and a lower heating power P ₂ . In particular, the upper heating power P ₁ is an average heating power of the inductor 18a over the cycle duration 22a, which is necessary to reach the setpoint temperature. In particular, the lower heating power P ₂ is an average heating power of the further inductor 20a, averaged over the cycle duration 22a, which is necessary to reach the setpoint temperature. $${\displaystyle \sum {\mathrm{P}}_{\mathrm{T}}={\mathrm{P}}_1+{\mathrm{P}}_2}$$

$${\mathrm{t}}_2=\left({\mathrm{P}}_2/{\displaystyle \sum {\mathrm{P}}_{\mathrm{T}}}\right)*{\mathrm{T}}_{\mathrm{C}}$$

The control unit 16a determines in particular an average heating output for a respective time sub-interval 24a, 26a as a function of the setpoint temperature and by varying the cycle duration. In particular, ignoring the switching time duration, the control unit 16a determines an average heating power for a respective time sub-interval 24a, 26a according to the formula $${\mathrm{t}}_1=\left({\mathrm{P}}_1/{\displaystyle \sum {\mathrm{P}}_{\mathrm{T}}}\right)*{\mathrm{T}}_{\mathrm{C}}$$

$${\mathrm{t}}_2=\left({\mathrm{P}}_2/{\displaystyle \sum {\mathrm{P}}_{\mathrm{T}}}\right)*{\mathrm{T}}_{\mathrm{C}}$$

In particular due to the switching time interval 28a, advantageously due to the switching time intervals 28a, there are fluctuations in an output power in the heating-up operating state, which in particular could result in flicker. In particular, the shorter the cycle duration 22a, the more likely it is that flicker will occur and/or the greater the effect if flicker will occur. The shorter the cycle duration 22a, the fewer thermal fluctuations there are in a temperature of a heating element 12a, 14a heated by an inductor 18a, 20a, which is particularly advantageous from a thermal point of view.

In particular, the greater the cycle duration 22a, the less likely it is that flicker will occur and/or the smaller the effect if flicker will occur. The greater the cycle duration 22a, the greater the thermal fluctuations in a temperature of a heating element 12a, 14a heated by an inductor 18a, 20a, which means that pulsed heating, in particular for an operator, is recognizable, which in particular results in a negative cooking experience for the operator results.

In particular, in the operating state, the control unit 16a selects the cycle duration 22a as a compromise between thermal fluctuations and low flicker. The control unit 16a selects the cycle duration 22a just long enough that flicker can be kept within the flicker standard and that thermal fluctuations are not recognizable to an operator and/or do not affect a cooking result.

The invention is based in particular on the finding that a variation of the cycle duration 22a in a range from 30 ms to 300 s, in particular from 1 s to 200 s, advantageously from 1.5 s to 100 s and particularly advantageously from 2 s to 60 s Cooking chamber temperature, and in particular a heating-up time, hardly and/or insignificantly affected, in particular although considerable thermal noise can be seen in a heating element 12a, 14a to be heated, which is particularly greater the greater the cycle duration 22a.

From the Figures 6 and 8 it can be seen in particular that thermal fluctuations in a heating element 12a, 14a to be heated vary depending on the selected cycle duration 22a. In particular, higher thermal fluctuations are permitted when the cooking chamber temperature is low, which in particular is at a large distance from the setpoint temperature, as a result of which a value for the cycle duration 22a can be selected to be greater. In particular, at a high cooking chamber temperature, which in particular is at a small distance from the setpoint temperature, smaller thermal fluctuations are permitted, as a result of which a smaller value for the cycle duration 22a should be selected in particular.

In particular, in the case in which the cooking chamber temperature assumes a value close to a value of the setpoint temperature, the control unit 16a could, for example, reduce a heating output to maintain the cooking chamber temperature, in particular to a heating output of a maximum of 1.8 kW, whereby the control unit 16a Inductor 18a and/or the further inductor 20a, in particular in each case, could be operated with a single heating frequency unit 76a, 78a. In this way, in particular, exceeding the target temperature due to thermal fluctuations can easily be avoided.

Reference sign

• 10a induction furnace device
• 12a heating element
• 14a Another heating element
• 16a control unit
• 18a inductor
• 20a Another inductor
• 22a cycle time
• 24a time division interval
• 26a 20 Another time sub-interval
• 28a switching time interval
• 30a time interval
• 32a Second time interval
• 34a Third time interval
• 36a Fourth time interval
• 38a supply unit
• 40a switching unit
• 42a induction furnace
• 44a muffle
• 46a cooking space
• 48a cooking appliance door
• 50a cooking chamber wall
• 52a bottom wall
• 54a ceiling wall
• 56a rear wall
• 58a side wall
• 60a side wall
• 62a operator interface
• 64a ordinate
• 66a abscissa
• 68a ordinate
• 70a abscissa
• 72a ordinate
• 74a abscissa
• 76a heating frequency unit
• 78a Another heating frequency unit
• 80a switching element
• 82a switch
• 84a Another switching element
• 86a switch
• 88a ordinate
• 90a abscissa
• 92a ordinate
• 94a abscissa
• 96a ordinate
• 98a abscissa
• 100a ordinate
• 102a abscissa
• 104a ordinate
• 106a abscissa
• 108a ordinate
• 110a abscissa

Claims (13)

1. Induction oven apparatus (10a) with at least one inductively heatable heating element (12a), with at least one control unit (16a) and with at least one inductor (18a), which is intended for inductive heating of the heating element (12a), characterised in that, in a heating-up operating state, the control unit (16a) operates the inductor (18a) in a pulsed and cyclical manner with at least one cycle duration (22a) and, in the heating-up operating state, ascertains the cycle duration (22a) as a function of at least one current heating parameter in relation to at least one reference heating parameter.
2. Induction oven apparatus (10a) according to claim 1, characterised in that the cycle duration (22a) has a value of at least 10 ms in at least one time interval (30a, 32a, 34a, 36a) of the heating-up operating state.
3. Induction oven apparatus (10a) according to claim 1 or 2, characterised in that the current heating parameter has a temperature.
4. Induction oven apparatus (10a) according to one of the preceding claims, characterised in that, in the heating-up operating state, the control unit (16a) operates the inductor (18a) with a shorter cycle duration (22a), the lower a difference is between the reference heating parameter and the current heating parameter.
5. Induction oven apparatus (10a) according to one of the preceding claims, characterised by at least one further inductor (20a), which operates the control unit (16a) in a pulsed manner in the heating-up operating state.
6. Induction oven apparatus (10a) according to claim 5, characterised in that, in the heating-up operating state, the control unit (16a) operates the inductor (18a) and the further inductor (20a) in an alternating pulsed manner.
7. Induction oven apparatus (10a) according to claim 5 or 6, characterised by at least one supply unit (38a) and by at least one switching unit (40a), by means of which, in the heating-up operating state, the control unit (16a) optionally electrically connects the inductor (18a) or the further inductor (20a) to the supply unit (38a).
8. Induction oven apparatus (10a) according to claim 7, characterised in that, in the heating-up operating state, the control unit (16a) switches the switching unit (40a) into a zero-current state.
9. Induction oven apparatus (10a) according to one of the preceding claims, characterised in that the inductor (18a) is intended to provide top heat and/or bottom heat.
10. Induction oven apparatus (10a) according to one of the preceding claims, characterised in that, in the heating-up operating state, the control unit (16a) operates the inductor (18a) with a heating output of at least 1.5 kW.
11. Induction oven apparatus (10a) according to one of the preceding claims, characterised by at least one cooking compartment wall (50a), which at least largely defines the heating element (12a).
12. Induction oven (42a) with at least one induction oven apparatus (10a) according to one of the preceding claims.
13. Method for operating an induction oven apparatus (10a), in particular according to one of claims 1 to 11, with at least one inductively heatable heating element (12a) and with at least one inductor (18a), which is intended for inductive heating of the heating element (12a), characterised in that, in a heating-up operating state the inductor (18a) is operated in a pulsed and cyclical manner with at least one cycle duration (22a) and, in the heating-up operating state, the cycle duration (22a) is ascertained as a function of at least one current heating parameter in relation to at least one reference heating parameter.

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